Hydraulic garage-jack



Dec. 5, 1961 L. H. LANDIN HYDRAULIC GARAGE-JACK 4 Sheets-Sheet 1 Filed Feb. 17, 1958 Dec. 5, 196-1 H. LANDIN 3,011,763

HYDRAULIC GARAGE-JACK Filed Feb. 1'7, 1958 4 Sheets-Sheet 2 Fig. 5.

Dec. 5, 1961 L. H. LANDIN HYDRAULIC GARAGE-JACK 4 Sheets-Sheet 3 Filed Feb. 1'7, 1958 IHHHII L and Lib Dec. 5, 1961 H. LANDIN HYDRAULIC GARAGE-JACK 4 Sheets-Sheet 4 Filed Feb. 1'7, 1958 n M. L

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INVENTOR L. h! Land/n ATTORNEYS United States PatentO 3,011,763 HYDRAULIC GARAGE-JACK Lars Herbert Landin, Kungsgatan 65, Eskilstuna, Sweden Filed Feb. 17, 1958, Ser. No. 715,698 Claims priority, application Sweden Nov. 15, 1957 3 Claims. (Cl. 254-2) The present invention relates to a hydraulic garage-jack provided with pump housing and preferably containing both a low pressure and a high pressure pump.

One object of the invention is to provide a hydraulic jack, which renders possible an easy location of the jack at the intended place below the vehicle and an easy attendance of the device.

A further object of the invention is to provide a hydraulic jack in which the jack and the pump housing are disposed at a comparatively great distance from each other and are rigidly secured to each other by means of a pipe structure forming an oil communication between the jack and the pump housing.

The invention further resides in the construction, combination and arrangement of parts illustrated in the accompanying drawings, and while there is shown therein a preferred embodiment, it is to be understood that the same is susceptible of modification and change, and comprehends other details, arrangements of parts, features and constructions without departing from the spirit of the invention.

In the drawings- FIG. 1 is a perspective view of a garage jack.

FIG. 2 shows the pumping apparatus in side view.

FIG. 3 is a plan view of the said apparatus.

FIG. 4 is a side view of the jack.

FIG. 5 is a plan view of the same.

FIG. 6 is a section taken along the line 66 of FIG. 5.

Referring to the drawings, a jack 1 and a pumping apparatus '2 are interconnected by means of a pipe struc- I. re 3, which extends approximately at right angles to the axis of the lifting piston. The distance between the jack and the pumping apparatus is comparatively great, preferably equal to the width of a motor vehicle, such as a bus or a truck. The jack involves in known manner an oil container, a working cylinder, into which leads a supply conduit for pressure oil, and a lifting piston 4 movable in said cylinder and influenced by return springs 5. The pumping apparatus consists of two pumps 6 and 7 having operating levers 8 and 9, respectively, one of said pumps being a low pressure pump for a rapid dsiplacement of the lifting piston and the other being a high pressure pump for lifting under a heavy load. Both pumps are in communication with a common pressure pipe 10, which in known manner communicates with the piston chamber of the jack. Said chamber of the jack communicates with a return pipe 11 for the pumps, which discharges into an oil chamber 12 (FIG. 2) provided in the pump housing and common to the pumps. Said pressure pipe and said return pipe may jointly form the pipe structure connecting the jack with the pumping apparatus or the pump housing and may serve as a stand. According to the embodiment shown, the stand structure includes two further pipes 13 and 14 located on either side of the two other pipes. Thus, the pipes 13 and 14 constitute a reinforcement of the stand, but they may be used as containers and conduits for oil.

The stand pipes 13 and 14 are, according to the shown example, extended beyond the pump housing, where they form shanks 15 and 16, respectively, for a loop shaped handle 17 bent somewhat upwards, by the aid of which the jack device may be pushed inwardly under the vehicle into the desired position.

In order to transport the jack in a convenient manner, wheels 18, 19 are mounted adjacent the jack, according to the example, on the side turned away from the pumps, as appears from FIGS. 1, 4 and 5. The wheels are capable of being hinged down from the position shown in FIG. 4 so as to carry the jack. For this purpose, the wheel axle 20, 21 isfixedly disposed at the end of an arm 22 rigidly secured to a shaft 23 which at 24 is mounted on the base member 25 of the jack. An arm 26 fastened to the shaft 23 is, at 27, pivotally connected to a link 28, which extends beyond the pumps and is articulated to an operating lever 29 (FIG. 2). This latter is swingable about a pin 30 rigidly secured to a bracket 31 on the pipe 16 by screws. The operating lever 29 is retained in the set position by means of a friction brake device consisting of a spring pressed washer 32 (FIG. 3), in which event the cooperating surfaces of the lever and washer may be corrugated. It is the intent of the friction brake that the jack upon the lifting of load will automatically be able to sink from an upper position determined by the conveying wheels into contact with the floor or the bed, in case no raising of the conveying wheels has taken place.

The pump housing is provided with stable feet 33 (FIG. 2), which are mounted on the stand pipes 13, 14 and are intended to protect the pipe structure against mechanical overload.

The jack constructed according to the invention is manageable and easily operated, and the pumps are of easy access for lifting movement. However, it is important that the load also should be able to be lowered from an elevated position to a lower position, or it should be possible to bring the jack out of engagement with the load by lowering the lifting piston. This is eflected by the aid of a hand wheel 34 (FIGS. 2 and 3), the rod 35 of which is associated with a valve screw provided in a discharge passage communicating with the pressure chamber of the lifting piston. The hand wheel 34 is provided adjacent the operating lever 29 and hence easily accessible.

The pump levers 8, 9 as well as the hand wheel 34 may be replaced by pedals, particularly in the case of jacks having a high lifting capacity.

In storing the device according to the invention, it is suitable to place it in a raised position and resting on the jack base 25. Since, however, the oil container of the jack partly contains air, it is important that this latter should not get any opportunity of penetrating into the system by way of stand pipes 13, 14. To prevent this, the oil container communicates with the standpipes by means of an open passage located on that side of the oil container of the jack which is turned away from the pump housing, whereby in the raised position of the aggregate said passage always is on a lower level than the oil and, thus, is separated from the air volume.

a modified pipe running. In this instance, the return pipe is omitted. The pipes 13, 14 which, through the intermediate of a transverse pipe 36 interconnecting said pipes, communicate with the oil chamber 12 of the pump housing and serve as oil containers from which said pumps can draw. The ends of the stand pipes 13, 14 connected to the jack communicate with channels 37, 38 respectively leading to that side of the oil container of the jack which is turned away from the pumping apparatus.

While I have described my improvements in great detail and with respect to one particular embodiment of the invention, I do not desire to be limited to such details and embodiment since many changes and modifications may be made and the invention embodied in widely different forms without departing from the scope and spirit thereof in its broader aspects.

FIGS. 3, 5 and 6 show by means of dot and dash lines,

What I claim is:

1. In a hydraulic jack, a lifting cylinder and piston means, a pump disposed at a distance from the lifting cylinder of the jack, a rigid pipe structure forming an oil communication between the lifting cylinder of the jack and the pump and fixed to said pump and to said jack, said pipe structure extending approximately at right angles to the axis of the lifting cylinder of the jack, transport wheels mounted adjacent the lifting cylinder of the jack, a mechanism for raising and lowering the jack relative to said wheels, a friction brake adapted to retain the jack in raised position, and an operating lever for said mechanism arranged adjacent the pump.

2. A hydraulic jack as claimed in claim 1, wherein the pipe structure is extended from said cylinder beyond the pump to form a handle, the operating lever for said mechanism for lowering or elevating said jack and operating levers for the pump being arranged adjacent said handle.

3. A hydraulic jack including a lifting cylinder and piston means, a pump housing, a first oil container for said 4 jack integral with said lifting cylinder, a rigid pipe structure fixed to said pump housing and to said first oil container including at least two oil containing pipes forming an additional oil container extending approximately at right angles to the vertical axis of said lifting cylinder and piston means of the jack, said pump housing being mounted on said rigid pipe structure at a distance from said lifting cylinder, at least one pump in said pump housing, the ends of the oil containing pipes of the pipe structure communicating with channels that discharge at the 7 side of said first oil container remote from said pump References Cited in the file of this patent UNITED STATES PATENTS Simmonds Ian. 17, 1950 Pearne Feb. 14, 1956 

